Interconnection pattern inspection method, manufacturing method of semiconductor device and inspection apparatus

ABSTRACT

A method of inspecting an interconnection pattern formed by depositing a metal onto a substrate having an interconnection pattern groove formed on a surface thereof includes: selectively measuring a thickness of a part above the substrate of a metal film formed on the substrate, the part above the substrate being a part constituted of the metal deposited upward from substantially the same surface as the surface of the substrate on which an interconnection pattern groove is formed; and evaluating how successfully the interconnection pattern groove is filled with the metal on the basis of a film thickness value obtained by the selective measurement.

CROSS REFERENCE TO RELATED APPLICATION

This is a division of application Ser No. 10/754,609, filed Jan. 12,2004, now U.S. Pat. No. 7,047,154, which is incorporated herein byreference.

This application claims benefit of priority under 35 USC §119 toJapanese Patent Application No. 2003-5883, filed on Jan. 14, 2003, thecontents of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of inspecting whether aninterconnection pattern groove formed on a surface of a substrate issuccessfully filled with a metal, and a manufacturing method of asemiconductor device using this inspection method and an inspectionapparatus. More specifically, the present invention relates to, forexample, an inspection of a degree to which a fine interconnectionpattern groove with a high aspect ratio is filled with a metal in amanufacturing process of an LSI (Large Scale Integrated Circuit) or aVLSI (very large scale integrated circuit) semiconductor devices.

2. Related Background Art

Hereinafter, in a process of inspecting whether an interconnectionpattern groove is successfully filled with a metal, an actualinterconnection pattern cannot be directly measured because of theminuteness of the actual interconnection pattern, difficulty in anon-contact type measurement of metal film thickness and so forth.Therefore, there has been used a method in which a pattern formeasurement is produced in a wafer and measuring this pattern to performan indirect inspection. Such indirect inspection methods include acontact method of measuring a sheet resistance of a pattern formeasurement by using a four-point probe method (e.g., Japanese PatentNo. 2559512), a method of managing a film thickness by observing apattern for measurement by using an optical microscope (e.g., JapanesePatent No. 2570130), a method of inspecting a filling degree of athrough hole on the basis of a change in a layer resistance by using thefour-point probe method or an eddy current method (e.g., Japanese PatentLaid Open (kokai) 10-154737) and others.

Since the method disclosed in Japanese Patent No. 2559512 is a contactmethod, it has a problem that an actual interconnection pattern cannotbe directly measured. In addition, the method disclosed in JapanesePatent No. 2570130 has a problem that automation and quantification aredifficult because of the measurement using an optical microscope.

Further, the method disclosed in Japanese Patent Laid Open (kokai)10-154737 uses a principle that a void generated in a metalinterconnection would contribute as a resistance to a flow of a currentwhen a void is. It measures a filling degree of a via on the basis of achange in a layer resistance, which increases in a defective productwith a void produced therein and, on the other hand, decreases the layerresistance in a non-defective product having no void.

However, with acceleration of minuteness in recent years, there haveincreased fine patterns such as a pattern with a high aspect ratio and asmall through hole diameter, a line with a very thin width and others.When trying to measure a change in a layer resistance in such a pattern,it is hard to detect a change in the layer resistance since a currentrarely flows through this fine pattern. Furthermore, in common with themethods mentioned above, there is a problem that an area in which apattern for measurement is produced must be assigned on a wafer.

In order to solve above problems, there has been recently developed amethod of directly inspecting an interconnection pattern. Examples ofsuch direct inspection methods include a destructive inspection methodin which a wafer is split off at a desired observation position andobserved by using an electron microscope, a non-destructive inspectionmethod in which a wafer having a bias voltage applied thereto isirradiated with electron beams and an inspection is carried out byobtaining a voltage contrast based on a phenomenon that the emissionquantity of secondary electrons varies depending on a conductivity(change in resistance) of a material embedded as an interconnection(e.g., Japanese Patent Laid Open (kokai) 2001-313322), and others.

However, the method disclosed in Japanese Patent Laid Open (kokai)10-154737 has a problem that considerable amounts of time and cost areconsumed since a plurality of steps are required before the measurement,as well as a restriction that this method cannot be used in a productwafer because of the destructive inspection.

Moreover, although the method disclosed in Japanese Patent Laid Open(kokai) 2001-313322 is expected as a method which can inspect a fillingdegree of an interconnection pattern groove in a product wafer in thenon-contact manner, there have been pointed out many problems that avery large and expensive apparatus is required as an inspectionapparatus since a complicated structure including a vacuum system isnecessary, a throughput is slow, the inspection cannot be stablyperformed and the like.

BRIEF SUMMARY OF THE INVENTION

According to a first aspect of the invention, there is provided a methodof inspecting an interconnection pattern formed by depositing a metalonto a substrate having an interconnection pattern groove formed on asurface thereof, comprising:

selectively measuring a thickness of a part above the substrate of ametal film formed on the substrate, the part above the substrate being apart constituted of the metal deposited upward from substantially thesame surface as the surface of the substrate on which an interconnectionpattern groove is formed; and

evaluating how successfully the interconnection pattern groove is filledwith the metal on the basis of a film thickness value obtained by theselective measurement.

According to a second aspect of the invention, there is provided amanufacturing method of a semiconductor device comprising a method ofinspecting an interconnection pattern formed by depositing a metal ontoa substrate having an, interconnection pattern groove formed on asurface thereof, the method of inspecting an interconnection patterncomprising:

selectively measuring a thickness of a part above the substrate of ametal film formed on the substrate, the part above the substrate being apart constituted of the metal deposited upward from substantially thesame surface as the surface of the substrate on which an interconnectionpattern groove is formed; and

evaluating how successfully the interconnection pattern groove is filledwith the metal on the basis of a film thickness value obtained by theselective measurement.

According to a third aspect of the invention, there is provided anapparatus to inspect an interconnection pattern, formed by a metaldeposited onto a substrate having an interconnection pattern grooveformed on a surface thereof, comprising:

a film thicknessmeter which selectively measures a film thickness of apart above the substrate of the metal film formed on the substrate, thepart above the substrate being a part constituted of the metal depositedupward from substantially the same surface with the surface of thesubstrate on which the interconnection pattern groove is formed; and

an evaluator which evaluates how successfully the interconnectionpattern groove is filled with the metal on the basis of a film thicknessvalue obtained by the film thicknessmeter.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1 to 5 are schematic cross-sectional views of wafers illustratingan inspection principle on which an interconnection pattern inspectionmethod according to the present invention is based;

FIG. 6 is a block diagram schematically showing an embodiment of theinspection apparatus according to the present invention;

FIG. 7A is a cross-sectional view showing a detailed structure of aneddy current loss measurement sensor unit incorporated in the inspectionapparatus depicted in FIG. 6;

FIG. 7B is a bottom view of the eddy current loss measurement sensorunit in the inspection apparatus depicted in FIG. 6;

FIG. 8 is a graph showing a part of a data content in a database D1stored in a memory of the inspection apparatus depicted in FIG. 6;

FIG. 9 is a graph showing another part of the data content in thedatabase D1 stored in the memory of the inspection apparatus depicted inFIG. 6;

FIG. 10 is a graph showing a part of a data content of a database D2stored in a memory of the inspection apparatus depicted in FIG. 6;

FIG. 11 is a flowchart showing a schematic procedure of a firstembodiment of an interconnection pattern inspection method according tothe present invention;

FIG. 12 shows a result of measuring a film thickness by scanning an areaA to an area C depicted in FIG. 2 by using an eddy current lossmeasurement sensor; and

FIG. 13 is a flowchart showing a schematic procedure of a secondembodiment of the interconnection pattern inspection method according tothe present invention.

DETAILED DESCRIPTION OF THE INVENTION

First of all, an inspection principle on which embodiments ofinterconnection pattern inspection methods according to the presentinvention is based will be briefly described below with reference toFIGS. 1 to 5.

FIGS. 1 to 5 are schematic cross-sectional views illustrating specificsteps of forming metal interconnections on a surface of a wafer.

In these cross-sectional views, grooves Gr for a line pattern or viawhich are used to form interconnections are previously formed on anupper surface of a wafer W by etching processing. By performing asputtering method, a plating method, a CVD (Chemical Vapor Deposition)method or the like onto the wafer W, a metal film MF is formed in such amanner that the interconnection pattern grooves Gr is filled with ametal material and the metal material still extends onto theirperipheral areas. As a result, interconnections are formed in theinterconnection pattern groove Gr. FIG. 1 and FIG. 4 show examples ofnon-defective products in which the interconnection pattern grooves Grare successfully filled with a metal. On the other hand, FIG. 2, FIG. 3and FIG. 5 show examples of defective products in which filling with themetal is not sufficiently carried out. It is to be noted that adifference in film shape between FIGS. 1 and 4 or a difference in filmshape between FIGS. 2 and 5 depends on a type or a shape (aspect ratio,size) of each interconnection pattern Pw, a pattern density, a filmformation method and the like.

In FIGS. 1 to 5, an area B is an area where the grooves Gr for theinterconnection patterns Pw are formed in the uppermost layer of thewafer W, and interconnection pattern grooves Gr are filled with themetal material in the area B by forming the metal film MF on the waferW, thereby forming the interconnection patterns Pw. Areas A and C areareas where the interconnection pattern grooves Gr are not formed in theuppermost layer.

When the interconnection pattern grooves Gr are normally filled with themetal, e.g., as shown in FIG. 1, large irregularities appear on asurface of the metal film MF1 in the area B. In FIG. 1 a film thicknessin the area B from the same surface as the upper face of the wafer W,i.e., the upper face of the interconnection patterns Pw, if theinterconnection patterns Pw are perfect interconnections, to the bottomsurfaces of the concave portions of the metal film MF1 is referred toTB1. The film thickness TB1 in the area B is thinner than a filmthickness TA of the metal film MF in the areas A and C. Additionally,e.g., as shown in FIG. 4, a film thickness TB7 from the same surface asthe upper face of the wafer W to the top surface of the metal film MF7in the area B is thinner than the film thickness TA in the areas A andC.

On the contrary, when filling with the metal is not normally carriedout, a difference between a film thickness of the metal film at a partdeposited upward from the same surface as the upper face of the wafer Win the area B and a film thickness of the metal film in the other areasA and C becomes smaller as a degree of filling defect increases.

For example, when a filling defect occurs in a film shape shown in FIG.1, since steps of irregularities on the metal film surface in the area Bbecome smaller as shown in FIG. 2, a film thickness TB3 from the samesurface as the upper face of the wafer W to the bottom surfaces of theconcave portions of the metal film MF3 in the area B is thicker than thefilm thickness TB1 shown in FIG. 1. Further, for example, when a fillingdefect occurs in a film shape shown in FIG. 4, a film thickness TB7 fromthe same surface as the upper face of the wafer W to the surface of themetal film MF7 becomes thicker like a film thickness TB9 of a metal filmMF9 shown in FIG. 5 simply in proportion to the degree of the fillingdefect. Furthermore, for example, when the interconnection patterngrooves Gr are not filled with the metal at all in the film shape shownin FIG. 1, a difference in film thickness between the areas A, B and Cbecomes zero as represented by a metal film MF5 in FIG. 3.

Therefore, information of the filling degree of the interconnectionpattern grooves Gr with the metal material can be acquired by monitoringa change in film thickness in the part of the metal film MF depositedupward from the same surface as the top face of the wafer W in the areaB, where the interconnection patterns Pw are formed, other than theinterconnection pattern groove inner portions. Here, as the density ofthe interconnection pattern grooves Gr is higher, a cubic content of themetal which fills the interconnection pattern grooves Gr (in the area B)and is still deposited upward from the same surface as the top face ofthe wafer W is more substantially reduced, and a difference between thefilm thickness TA and the film thickness TB becomes larger. Therefore,by performing the measurement in the area with the high density of theinterconnection pattern grooves Gr, the film thicknesses TA and TB and achange can be more prominently measured in accordance with a fillingdegree of the interconnection pattern grooves Gr with the metal materialas compared with the measurement in the area with the low density of theinterconnection pattern grooves Gr, thereby improving a measurementaccuracy. Typical measurement methods for such an inspection include afour-point probe type for a contact mode, an optical type, an opticalacoustic type, an X-ray type and an eddy current type for a non-contactmode. However, the measurement can be performed by using a metal filmthicknessmeter which is of an arbitrary measurement type.

Some embodiments according to the present invention will now bedescribed hereinafter with reference to FIGS. 6 to 13. In the followingembodiments, a description will be given as to the case that an eddycurrent type film thicknessmeter is taken as an example of the filmthicknessmeter.

FIG. 6 is a block diagram schematically showing an embodiment of aninspection apparatus according to the present invention. An inspectionapparatus 1 shown in this drawing comprises an eddy current lossmeasurement sensor unit 10, an impedance analyzer 20, a displacementsensor controller 30, a control computer 40, a memory MR, an X-Y-Z stage50, and a stage driver 60. The eddy current loss measurement sensor unit10 includes an eddy current loss measurement sensor 11, a capacitancetype displacement sensor 13, and a Z stage 17. The memory MR isconnected to the control computer 40, and stores databases D1 and D2which will be described later. The impedance analyzer 20, thedisplacement sensor controller 30 and the stage driver 60 are connectedto the control computer 40, and respectively receive command signalsfrom the control computer 40. The X-Y-Z stage 50 supports a wafer W onan upper face thereof, is connected to the stage driver 60 to therebyreceive a drive signal, and moves the wafer W in three directions of X,Y and Z without restraint. The Z stage 17 is also connected to the stagedriver 60 and receives a drive signal to move the eddy current lossmeasurement sensor unit 10 in the direction Z. The capacitance typedisplacement sensor 13 of the eddy current loss measurement sensor unit10 is connected to the displacement sensor controller 30, and thedisplacement sensor controller 30 measures a change in capacitancebetween a capacitance type displacement sensor electrode 13 EL (see FIG.7B) and a metal film MF and transmits a measurement result to thecontrol computer 40.

FIGS. 7A and 7B are explanatory views showing the eddy current lossmeasurement sensor unit 10 in more detail. FIG. 7A shows a partial frontview of the eddy current loss measurement sensor unit 10 together with apartial cross-sectional view of the wafer W having the metal film MFformed on the upper face thereof. FIG. 7B shows a bottom view of theeddy current loss measurement sensor unit 10.

The eddy current loss measurement sensor 11 has an excitation-receptionintegrated coil L, is connected to the impedance analyzer 20, andreceives a supply of a high-frequency current from the impedanceanalyzer 20 to excite a high-frequency magnetic field by using the coilL. The eddy current loss measurement sensor 11 is configured in such amanner that a line of magnetic flux MFL (see FIG. 7A) of a magneticfield to be excited locally passes through a surface layer of the metalfilm MF when this sensor is positioned above the metal film MF of thewafer W. An eddy current is excited in the metal film MF by thismagnetic field, and there is generated an eddy current loss P which isin proportion to a square of a frequency f of the high-frequency currentand a film thickness t of the metal film MF and in inverse proportion toa resistivity ρ of the metal film MF as represented by the followingexpression.P∝(f ²·t)/ρ

When the current loss P is generated in the metal film MF, the eddycurrent loss measurement sensor 11 receives a resultant magnetic fieldof a magnetic field generated from the eddy current and a magnetic fieldexcited by the coil L. Consequently, an impedance of the eddy currentloss measurement sensor 11 and a current value or a phase of thehigh-frequency current supplied from the impedance analyzer 20 to thecoil L of the eddy current loss measurement sensor 11 are changed inaccordance with the film thicknesses TA and TB of the metal film MF. Theimpedance analyzer 20 measures this change, and transmits a measurementresult to the control computer 40.

As shown in FIG. 7B, the capacitance type displacement sensor 13 has asensor electrode 13 EL provided so as to be wound around the bottomportion of the coil L of the eddy current loss measurement sensor 11 viaan insulating material 15 formed so as to cover the excitation-receptionintegrated coil L. The sensor electrode 13 EL is connected to thedisplacement sensor controller 30, and the displacement sensorcontroller 30 is connected to the ground via an interconnection (notshown). The metal film MF is also connected to the ground through aninterconnection (not shown). As a result, the capacitance typedisplacement sensor electrode 13 EL and the electroconductive film MFconstitute electrodes on both sides of a capacitor. As shown in FIG. 7A,in this embodiment, the sensor electrode 13 EL is arranged in such amanner that its bottom face and a bottom face of the eddy current lossmeasurement sensor 11 are positioned on the same plane, and acapacitance between the capacitance type displacement sensor electrode13 EL and the metal film MF is thereby changed in accordance with adisplacement between the eddy current loss measurement sensor unit 10and the metal film MF. The displacement sensor controller 30 detectsthis change in capacitance, and transmits its result to the controlcomputer 40. The capacitance type displacement sensor 13 can measure acapacitance over an area sufficiently wider than an interconnectionpattern formation area B, and a displacement measurement result isintegrated in a plane of the sensor electrode 13 EL. Therefore, theaffect of irregularities on the interconnection pattern surface can besuppressed to the very low level.

Again referring to FIG. 6, the control computer 40 effects the impedanceanalyzer 20 to supply a high-frequency current to the eddy current lossmeasurement sensor 11, and operates the X-Y-Z stage 50 or the X-Y-Zstage 50 and the Z stage 17 through the stage driver 60 while measuringa displacement between the eddy current loss measurement sensor 11 andthe metal film MF by using the capacitance type displacement sensor 13through the displacement sensor controller 30, thereby scanning asurface area of the wafer W. During this scanning, the control computer40 receives a measurement result of the eddy current loss measurementsensor 11 from the impedance analyzer 20 and, at the same time,calculates a film thickness of the metal film MF by making reference tothe databases D1 and D2 stored in the memory MR.

A method of controlling the X-Y-Z stage 50 and the Z stage 17 utilizinga measurement result of the capacitance type displacement sensor 13includes a method of measuring an eddy current loss while maintaining adistance between the metal film MF on the wafer W and the eddy currentloss measurement sensor 11 constant, and a method of executingcorrection processing with respect to an eddy current loss measuredvalue obtained from the eddy current loss measurement sensor 11 by usinga measurement result of a displacement between the eddy current lossmeasurement sensor 11 and the metal film MF without operating the Zstage 17.

A resistance is high in a portion of the metal film constituted by partsof small cubic contents like the portion of the interconnection pattern.Pw or the portion with irregular surface in the area B above theinterconnection pattern Pw (see, e.g., FIG. 1). In principle, the eddycurrent has characteristics that it has difficulty in flowing through anarea with such a high resistance. As a result, a film thickness TB at apart constituted of the metal deposited upward from the same surface asthe surface (surface on which the metal film MF is formed) of the waferW (which will be simply referred to as a part above the substratehereinafter) and a film thickness (TB+TP) are selectively measuredrather than a thickness of the metal deposited within theinterconnection pattern Pw. Further, in the film thickness measurementbased on the eddy current loss like this embodiment, a relatively widearea is collectively measured, and there can be acquired a measurementresult obtained by integrating a film thickness at the part above thesubstrate in the entire measurement area. Therefore, changes in the filmthickness TA and the film thickness TB can be more noticeably measuredin accordance with a filling degree of the interconnection patterngrooves Gr with the metal material as more interconnection patterns Pware formed with a higher density, thereby improving the measurementaccuracy.

A description will now be given as to the databases D1 and D2 which arestored in the memory MR and used in a film thickness calculation of themetal film at the part above the substrate.

In the database D1, data representing a relationship between changes inimpedance of the eddy current loss measurement sensor 11, changes in acurrent quantity and a phase of a high-frequency current supplied fromthe impedance analyzer 20 to the coil L, a film thickness and aresistivity ρ of the metal film at the part above the substrate, and adisplacement between the metal film and the eddy current lossmeasurement sensor is previously measured and prepared. FIGS. 8 and 9show examples of such data. FIG. 8 shows an example of a graph in whichchanges in an inductance and a resistivity of the eddy current lossmeasurement sensor 11 relative to a displacement between the eddycurrent loss measurement sensor 11 and the metal film MF are plottedwith a film thickness of the metal film MF at the part above thesubstrate being used as a parameter. Furthermore, FIG. 9 shows anexample of a graph in which a relationship between a film thickness ofthe metal film MF at the part above the substrate and an inductance anda resistivity of the eddy current loss measurement sensor 11 is plottedwith a difference in resistivity ρ of the metal film MF being used as aparameter. The control computer 40 converts a measurement result of theeddy current loss measurement sensor 11 supplied from the impedanceanalyzer 20 into a film thickness of the metal film MF at the part abovethe substrate by making reference to such a database D1.

In the database D2, data representing a relationship between a filmthickness of the metal film MF at the part above the substrate and afilling ratio of the interconnection pattern grooves Gr is previouslymeasured and prepared. FIG. 10 shows an example of such data. Thisdrawing is a graph in which a correlation between a maximum filmthickness difference of the metal film MF at the part above thesubstrate and a filling ratio of the interconnection pattern grooves Gris plotted. The control computer 40 calculates a film thicknessdifference between the areas A and C where the interconnection patterngrooves Gr are not formed and the area B where the interconnectionpattern grooves Gr are formed from film thickness values of the metalfilm MF at the part above the substrate obtained by scanning the waferW, calculates a filling ratio of the interconnection grooves Gr with themetal by making reference to the database D2, and outputs a result.

A first embodiment of an interconnection pattern inspection method usingthe inspection apparatus 1 depicted in FIG. 6 will now be described withreference to a flowchart of FIG. 11.

First, a frequency of a high-frequency current supplied from theimpedance analyzer 20 to the eddy current loss measurement sensor 11 isset to a value optimum for a target film thickness with reference to thetarget film thickness aimed in forming the metal film MF of the wafer W(step S1). A range of a variable frequency is, e.g., 1 MHz to 10 MHz.

Then, the X-Y-Z stage 50 or both the X-Y-Z stage 50 and the Z stage 17are driven while a high-frequency magnetic field is excited by ahigh-frequency current supplied from the impedance analyzer 20 to theeddy current loss measurement sensor 11 at the set frequency. As aresult, the eddy current loss measurement sensor 11 is used to scan themetal film MF from the area A where the interconnection pattern groovesGr are not formed to the area C where the interconnection patterngrooves Gr are not formed through the area B where the interconnectionpattern grooves Gr are formed, thereby measuring film thicknesses of themetal film MF at the part above the substrate (step S2).

Subsequently, the maximum value of a film thickness difference in theareas scanned by the eddy current loss measurement sensor 11 iscalculated from the film thickness measurement result (step S3). FIG. 12shows a measurement result obtained by scanning the metal film MF fromthe area A to the area C depicted in FIG. 2 as an example of such a filmthickness measurement result.

At last, a filling ratio of the interconnection pattern grooves Gr withthe metal is calculated with respect to the interconnection pattern Pwto be measured on the basis of a correlation between the maximum filmthickness difference of the metal film at the part above the substrateand the filling ratio of the interconnection pattern grooves which isstored in the memory MR as the database D2 (see FIG. 6), and an obtainedresult is outputted (FIG. 11, a step S4).

Here, for example, a value of 80% in FIG. 10 can be set as a thresholdvalue to be used to judge the quality of a product, and a product can bejudged as a non-defective one when a calculated filling ratio exceeds80%.

FIG. 13 is a flowchart showing a schematic procedure of a secondembodiment of an interconnection pattern inspection method using theinspection apparatus 1. In this embodiment, as the database D2 stored inthe memory MR, there is previously prepared a relationship (not shown)between a minimum film thickness value of the metal film MF at the partabove the substrate measured in the area B of a non-defective producthaving the interconnection pattern grooves Gr sufficiently filled withthe metal and a filling ratio of the interconnection pattern grooves Gr.

First, like the first embodiment, a frequency of a high-frequencycurrent to be supplied to the eddy current loss measurement sensor 11 isset to a value optimum for a target film thickness of the metal film MF(step. S11). Then, only the area B where the interconnection patterngrooves Gr are formed is scanned without scanning the areas A and Cwhere the interconnection pattern grooves Gr are not formed and onlyfilm thicknesses of the part above the substrate of the metal film. MFare measured (step S12). At last, a minimum film thickness value istaken out from the obtained film thickness values, and a filling ratioof the interconnection grooves Gr with the metal is calculated withrespect to the interconnection patterns Pw to be measured from theminimum film thickness value in the area B with reference to therelationship (not shown) between the minimum film thickness value andthe filling ratio in the interconnection pattern grooves Gr prepared asthe database D2 (step S13).

By measuring exclusively the film thicknesses of the metal film MF atthe part above the substrate in the area B where the interconnectionpattern grooves Gr are formed, the filling ratio of the interconnectionpattern grooves Gr with the metal can thus be calculated.

According to the above-described embodiments, it is possible to readilyevaluate a filling degree with the metal in the very fineinterconnection pattern grooves with a high aspect ratio which is hardto be measured in the prior art. Moreover, since a product wafer can bedirectly measured in the non-contact manner, the inspection steps can besubstantially simplified.

Additionally, according to the foregoing embodiments, since the eddycurrent mode is adopted, a high-speed measurement is possible with thesimple and small measurement system, and the non-contact type in-lineand in-situ measurement and inspection can be performed in the filmformation device.

Further, a semiconductor device can be manufactured with a high yieldratio and a high throughput by producing the semiconductor deviceutilizing the above-described inspection methods.

Although some of the embodiments according to the present invention havebeen described, the present invention is not restricted thereto, and itcan be modified and carried out within the scope thereof. Although thedescription has been given as to the case that a product pattern isdirectly measured in the inspection method mentioned above, this methodcan be also used in measurement of an inspection pattern.

Furthermore, although the apparatus including the single eddy currentloss measurement sensor 11 is taken as an example in the description ofthe embodiment of the inspection apparatus, the throughput can befurther improved by arranging a plurality of eddy current lossmeasurement sensors 11 in the measurement apparatus, or a plurality ofchips on the wafer surface can be simultaneously measured and inspected.

Moreover, the in-line and in-situ measurement in vacuum is enabled byincorporating the above-described inspection apparatus in a filmformation system. In order to perform the in-situ measurement duringfilm formation, arranging the eddy current loss measurement sensor 11 ona rear surface side of the wafer W can suffice.

Additionally, although the eddy current mode has been described indetail in the foregoing embodiments, a filling degree of the pattern canbe readily measured like the eddy current mode by using theabove-described measurement method and measurement algorithm even if ametal film thickness measurement apparatus adopting any other mode isutilized.

1. A method of inspecting an interconnection pattern formed bydepositing a metal onto a substrate having an interconnection patterngroove formed on a surface thereof, comprising: selectively measuring athickness of a first part of a metal film above the substrate in anon-contact and non-destructive manner, the metal film being formed onthe substrate and having the first part and a second part, the firstpart of the metal film constituted of the metal deposited upward fromsubstantially the same surface as the surface of the substrate on whichan interconnection pattern groove is formed, the second part of themetal film being constituted of the metal deposited within theinterconnection pattern groove; previously preparing a relationshipbetween a film thickness value of the first part and a filling ratio inthe interconnection pattern groove; and evaluating, by an evaluator, howsuccessfully the interconnection pattern groove is filled with the metalon the basis of a film thickness value obtained by the selectivemeasurement and the relationship between the film thickness value of thefirst part and the filling ratio in the interconnection pattern groove,without measurement of a thickness of the second part of the metal film.2. The method of inspecting an interconnection pattern according toclaim 1, wherein the thickness of the first part of the metal film iscalculated based on a value of an eddy current loss obtained by excitingan eddy current on a surface of the metal film and measuring an eddycurrent loss generated by this excitation.
 3. The method of inspectingan interconnection pattern according to claim 2, wherein the eddycurrent is excited by using an eddy current loss measurement sensorwhich receives a high-frequency current to excite a high-frequencymagnetic field, and a frequency of the high-frequency current is set inaccordance with a target film thickness during formation of the metalfilm.
 4. The method of inspecting an interconnection pattern accordingto claim 1, wherein the evaluation of how successfully theinterconnection pattern groove is filled with the metal is executedconcurrently with formation of the interconnection pattern.
 5. Amanufacturing method of a semiconductor device comprising a method ofinspecting an interconnection pattern formed by depositing a metal ontoa substrate having an interconnection pattern groove formed on a surfacethereof, said method of inspecting an interconnection patterncomprising: selectively measuring a thickness of a first part of a metalfilm above the substrate in a non-contact and non-destructive manner,the metal film being formed on the substrate and having the first partand a second part, the first part of the metal film being constituted ofthe metal deposited upward from substantially the same surface as thesurface of the substrate on which an interconnection pattern groove isformed, the second part of the metal film being constituted of the metaldeposited within the interconnection pattern groove; previouslypreparing a relationship between a film thickness value of the firstpart and a filling ratio in the interconnection pattern groove; andevaluating, by an evaluator, how successfully the interconnectionpattern groove is filled with the metal on the basis of a film thicknessvalue obtained by the selective measurement and the relationship betweenthe film thickness value of the first part and the filling ratio in theinterconnection pattern groove, without measurement of a thickness ofthe second part of the metal film.
 6. The method of manufacturing asemiconductor device according to claim 5, wherein the thickness of thefirst part of the metal film is calculated based on a value of an eddycurrent loss obtained by exciting an eddy current on a surface of themetal film and measuring an eddy current loss generated by thisexcitation.
 7. The method of manufacturing a semiconductor deviceaccording to claim 6, wherein the eddy current is excited by using aneddy current loss measurement sensor which receives a high-frequencycurrent to excite a high-frequency magnetic field, and a frequency ofthe high-frequency current is set in accordance with a target filmthickness during formation of the metal film.
 8. An apparatus to inspectan interconnection pattern formed by a metal deposited onto a substratehaving an interconnection pattern groove formed on a surface thereof,comprising: a film thicknessmeter which selectively measures a thicknessof a first part of a metal film above the substrate in a non-contact andnon-destructive manner, the metal film being formed on the substrate andhaving the first part and a second part, the first part of the metalfilm being constituted of the metal deposited upward from substantiallythe same surface as the surface of the substrate on which theinterconnection pattern groove is formed, the second part of the metalfilm being constituted of the metal deposited within the interconnectionpattern groove; and an evaluator which evaluates how successfully theinterconnection pattern groove is filled with the metal on the basis ofa film thickness value obtained by the film thicknessmeter and apreviously prepared relationship between a film thickness value of thefirst Part and a filling ratio in the interconnection pattern groove,without measurement of a thickness of the second part of the metal film.9. The inspection apparatus according to claim 8, wherein the filmthicknessmeter includes an eddy current loss measurement sensor whichexcites an eddy current on a surface of the metal film by exciting ahigh-frequency magnetic field upon receiving a high-frequency currentand measures an eddy current loss generated thereby.
 10. The inspectionapparatus according to claim 9, wherein a frequency of thehigh-frequency current is set in accordance with a target film thicknessduring formation of the metal film.
 11. The inspection apparatusaccording to claim 8, wherein the inspection apparatus is provided in afilm formation system which receives the substrate and forms a metalfilm on the substrate, and evaluates how successfully theinterconnection pattern groove is filled with the metal concurrentlywith formation of the interconnection pattern.
 12. A method ofinspecting an interconnection pattern formed by depositing a metal ontoa substrate having a groove formed on a surface thereof, comprising:selectively measuring a thickness of a first part of a metal film abovethe substrate in a non-contact and non-destructive manner, the metalfilm being formed on the substrate and having the first part and asecond part, the first part of the metal film being constituted of themetal deposited upward from substantially the same surface as thesurface of the substrate on which a groove is formed, the second part ofthe metal film being constituted of the metal deposited within thegroove, the groove having been formed using etching so as to have ashape of an interconnection pattern; previously preparing a relationshipbetween a film thickness value of the first part and a filling ratio inthe interconnection pattern groove; and evaluating, by an evaluator, howsuccessfully the groove is filled with the metal on the basis of a filmthickness value obtained by the selective measurement and therelationship between the film thickness value of the first part and thefilling ratio in the interconnection pattern groove, without measurementof a thickness of the second part of the metal film.
 13. A manufacturingmethod of a semiconductor device comprising a method of inspecting aninterconnection pattern formed by depositing a metal onto a substratehaving an interconnection pattern groove formed on a surface thereof,said method of inspecting an interconnection pattern comprising:selectively measuring a thickness of a first part of a metal film abovethe substrate in a non-contact and non-destructive manner, the metalfilm being formed on the substrate and having the first part and asecond part, the first part of the metal film being constituted of themetal deposited upward from substantially the same surface as thesurface of the substrate on which a groove is formed, the second part ofthe metal film being constituted of the metal deposited within thegroove, the groove having been formed using etching so as to have ashape of an interconnection pattern; previously preparing a relationshipbetween a film thickness value of the first part and a filling ratio inthe interconnection pattern groove; and evaluating, by an evaluator, howsuccessfully the groove is filled with the metal on the basis of a filmthickness value obtained by the selective measurement and therelationship between the film thickness value of the first part and thefilling ratio in the interconnection pattern groove, without measurementof a thickness of the second part of the metal film.
 14. An apparatus toinspect an interconnection pattern formed by a metal deposited onto asubstrate having a groove formed on a surface thereof, comprising: afilm thicknessmeter which selectively measures a film thickness of afirst part of the metal film formed on the substrate in a non-contactand non-destructive manner, the metal film being formed on the substrateand having the first part and a second part, the first part above thesubstrate being constituted of the metal deposited upward fromsubstantially the same surface the surface of the substrate on which agroove is formed, the second part of the metal film being constituted ofthe metal deposited within the groove, the groove having been formedusing etching so as to have a shape of the interconnection pattern; andan evaluator which evaluates how successfully the interconnectionpattern groove is filled with the metal on the basis of a film thicknessvalue obtained by the film thicknessmeter and a previously preparedrelationship between a film thickness value of the first part and afilling ratio in the interconnection pattern groove, without measurementof a thickness of the second part of the metal film.